MC68HC08AS32 Datasheet, PDF (137/280 Pages) Motorola, Inc – M68HC08 Family of 8-bit microcontroller units (MCUs)

Data Sheet — MC68HC08AS32
Section 10. Mask Options
10.1 Introduction
This section describes use of mask options by custom-masked read-only memory
(ROMs) and the mask option register in the MC68HC08AS32.
10.2 Functional Description
The mask options are hard-wired connections, specified at the same time as the
ROM code, which allow the user to customize the MCU. The options control the
enable or disable ability of the following functions:
• ROM security⁽¹⁾
• Resets caused by the LVI module
• Power to the LVI module
• Stop mode recovery time (32 CGMXCLK cycles or 4096 CGMXCLK cycles)
• COP timeout period (2¹⁸–2⁴ CGMXCLK cycles or 2¹³â€“2⁴ CGMXCLK
cycles)
• STOP instruction
• Computer operating properly module (COP)
The mask option register ($001F) is used in the initialization of various options. For
error free compatibility with the emulator OTP (M68HC908AT32CFN), a write to
$001F in the MC68HC08AS32 has no effect in MCU operation.
10.3 Mask Option Register
Address:
Read:
Write:
Reset:
$001F
Bit 7
LVISTOP
R
R
6
ROMSEC
R
5
LVIRST
R
= Reserved
4
3
LVIPWR SSREC
R
R
Unaffected by reset
2
COPRS
R
Figure 10-1. Mask Option Register (MOR)
1
STOP
R
Bit 0
COPD
R
1. No security feature is absolutely secure. However, Freescale’s strategy is to make reading or
copying the ROM data difficult for unauthorized users.
MC68HC08AS32 — Rev. 4.1
Freescale Semiconductor
Data Sheet
137